Effects of low energy N~+ ion beam implantation on Stevia rebaudiana seeds

Dry seeds of Stevia rebaudiana were implanted with different dose of low energy N+ion beam.The results showed as follows: stevia germination rate was promoted by low dose of N+ ion beam,inhibited by high dose;the plant height and the steviol glycosides content presented " saddle like model" which decreased at the begin,then increased and decreased further again with increase of irradiation doses;mutational spectra,including plant heights,more leaf numbers,large leaves and high steviol glycosides content were selected after irradiation.